Transmission and control mechanism



May 17, 19:52n

L F. NENNINGER TRANSIISSION AND GONTRQL IECLHANISI Filed July 19,l 1939 Patented May 17, 1932v i UNITED STATES4 PATENT loFFlcla: y

LESTER F. NENNINGER, OF CINCINNATI, OHIO, ASSIGNOR TO TH (.'IINI'NA'IIIIV MILLING "MACHINE COMPANY, F CINCINNATI, OHIO, A CORPORATION OF OHIO TRANSMISSION im coN'rnoL uncnamsn Application and .my 1a, 1930. sriarno. 469,071.

This invention .relates to milling machines v and more particularly to'a transmission and control mechanism ,therefon One of the princlpal objects of this invention is the provision of an improved transmission 'suitable for general machine tool use which will oifer an eilicient and economical selection of speeds and torques.

A further object of this invention is to provide a variable speed transmission from which a wide range of speeds may be ob' tained through a minimum number of gear contacts for each speed thereby permitting the transmission of a maximum amount of power for each speed.

A still further object of this invention is to provide interlocking means Vfor three sets ofI modifications mayl be made in the specific structural details reinafter disclosed within the scope of the appended claims without departing "from or lexceeding the spirit of the invention.

Referring to the drawings in which like reference numerals indicate like parts:

Figure 1 isan elevation of a machine tool showing an expanded view of the vtransmission embodied therein.

Fi re 2 is a view taken substantially on the line 2-2'01 Fi re 1. o Fi2gure 3 is a section on the line'3-3 of Figure Y A Figure 4 is a detail of the shifter rods and operating mechanism therefor.`

Figure 5 is a detail view of the control levers. l Y

Figure 6 is a section on the line 6-6of Figure 3.

l The economical.requirements lof a-y variable speed transmission suitable for machine tool usel demand that the maximum, amount of power for each speed be'delivered to the actuated part from the prime mover, or in other words, that the loss of power in the transmission` due to friction and other causes should be maintained Iat a minimum. One of the major sources of friction losses in vari# able speed transmissions is the large number of gear contacts necessary to the transmission of a given speed, from which it is seen that the smaller the number of gearsy utilized to effect an increase or decrease of s eed from one' part to another the more e cient the transmission will be.

A variable speed transmission for use in machine tools should also have a suitablel speed range in order that the proper rate of lrelative movement as between the tool and work for instance, may be selected to eiect stock removal 'in a` reasonable time with due regard to the character and amount of material to be removed as well as the type of cutting tool utilized and the finish desired.

In some machine tools and more particularly in milling machines having a rotating cutter spindle, a transmission is needed that is capable in addition to transmitting a plurality of speeds to the cutter spindle, of imparting various torques thereto, to meet the varying demands placed upon the cuttin tools. These demands vary with the type o cutter and sizeof cut, some cutters requiring Aa low speed and high torque, while other types havin high speed cutting tips capable of withstan ing relatively great heat require an extremely high speed andsmall `torque in 'order to eiliciently utilize them.

In many instances a suitable torque may be available in the final member, but due tothe relationship of the diameter of the cutter to `the diameter of the final ear which drives it,

a mechanical advantage 1s lost which results. .in an ineilcient drive.- vAn eilicient transmission should therefore, have in addition to a. suitable range of speeds and torques, final .membersl which are capable of maintaining a mechanical advantage over the parts to be. -driven thereby..l A f From the foregoing desiderata itshould be apparent that a transmission inorder to be satisfactory for general machine tool use must be highly iiexible, capable of high speeds, variable to obtain` low speeds with great 10ovv support organization comprising mesh with the gear 21 actuated thereby.

Inorder to more full understand the invention, reference may ge had to the accompanying drawings, mission which Vsatisfies the above requirements and is capable of delivering sultable speeds and torques to meet the diversified requirements of modern machine tools and which has the necessary attributes suitable to its application tosuch highly developed precision tools, as milling machines, and ca.- .pable of satisfactorily fulfilling the various demands made upon the transmissions of such machines.

In the drawings,

to a machine tool, in the present instance a milling machine, which has a base and a column 11 upon which is mounted a work a knee 12 which supports a saddle 13 upon which is mounted a work table 14. A tool spindle,

such as 15, is journaled in theupper partv of the column. The transmission herein disclosed is coupled with .the tool Spindle 15 .for actuation thereof and is to be considered as'an illustration of one application of the transmission since it is readily apparent to those skilled in the art that the transmission is equally adaptable for effecting movement of other elements, such as the work supporting members.

The prime mover, such as Y the base of themachine may be used to operate the primary shaft 17 of the variable speed transmission which has the shiftable gear couplets 18 and 19 mounted thereon. The couplet 18 includes the gear 20 shiftable into and the gear 22 shiftable into mesh with the gear 23. The gear couplet 19 comprises the gears 24 and 25 shiftable respectively into engagementwith the gears 26 land 27. The driven gears are fixed to shaft 28 which is journaled in a fixed part of the machine parallel to the shaft 17. Any suitable known means-may be used for shifting 'the gear cou different-rates of speed in the driven shaft 28. Slidably mounted on the end of shaft 28 is the gear 29 adapted to be shifted to the left to mesh direct ywith gear 30l or to the right to mesh with gear 31. The latter, together with the gear 32, constitutes a reversing mechanism whereby the gear 30 may be driven in either direction from the gear 29.-

The ear 30 is fixed on the end of a shaft 33 which as a plurality of back .gear units splined thereon. In the present instance these units are shown closely coupled with the gear although it may be necessary or more desirable inother types of installation to exl tend the shaft 30thereby having the variable plurality 1n which is shown a transl be shifted Flgure 1 shows the appl,` -cation of the transmission of this invention 16, mounted in 'letsto effect the four any one of these units into power with resultant breakage of parts.

shifter rod -45 has `which enga speed transmission at a moreconvenientl location and the back gear units remote therefrom adjacent the part The units 34 and 35 are splined on the shaft 33 and adapted to mesh of back gears keyed to the cutter spindle. The'"back gear couplet 34 is shift-4 able to the left to engage ear36 and to the right to engage gear 37, w 'le theV gear couplet is shiftable to the leftyto engage gear 38 or to the right to engag'egear39. 'The gear couplet 35 includes the: 39 which is in constant enga ment with the elongated pinion 40 which 1n turn actuates the couplet 41 through the gear 42. The smaller gear 43 of this couplet is adapted to` ment with the gear 39. From the description it should now be apparent that the spindle 15 is adapted to be driven from the shaft 33` through anyone of five different back gear ratios, which in combination withthc vaable gear couplet which means that each gear transmits eight different speeds of revolution and, therefore, has eight different peripheral velocities. Since it is desirable to rotate all gears at an ellicient peripheral velccity, such as 800 feet per minute, it isevident that in the transmission of such a wide range of speeds through a single gear that the peripheral velocities at certain speeds would be unsatisfactory. This difficulty has been overcome in the present invention` by arranging the mechanism so that only four different rotational rates. are transmitted through a single gear to choose gear sizes which will produce satisfactory peripheral velocities for all speeds. This arrangement also reduces the number i of gear contacts for each speed thereby reducthe power l ing frictional losses and increasing transmitted.

The back gear pairs are 4divided as previously described, into three` shiftable units with either one of a thus making it possible 1 to be driven thereby.

pinion member A to the left into drivingengagel and means havebeen provided for shifting A transmitting position, and simultaneously locking the other units in neutral to insure against the simultaneous engagement of two gear pairs To this end shifter rods, such as 44, 45 and 46 are slidably mounted in a side ofthe column land provided with a shifter arm fixed therewith. The rod 44 has integrally connected therewith` shifter arm 48 which engages the sides of the gear 42. The the bifurcated arm 49 es the gear 50 .of the couplet 34 and the shi r rod 46 has the arm '51 with a forked end which engages the gear 52. Each of the rods 44, 45 and 46 is provided with a bracket 47 attached tothe rack portion, such as 53, and a inion gear 54 mounted on the end of a shaft 55 is provided to mesh with each rack portion. Rotation of any pinion will causey subsequent shiftingof its respective arm.' T heshafts 55 are provided on their exterior extremities with handles 56 for the manual actuation thereof.

In order to prevent the actuation 'of more than one' shifter rod-at a time, interlocking means have been provided between the three shiftable units. This is accomplished by providin an interlock between shifter rod 45 and t e shifter rod 46 whereby movement of one to a power transmitting position will prevent movement of the other, which may take the form of a pivoted disk 57 mounted on the end of the block 59 fixed to the bracket 47. This disk has two arcuate shaped lugs 62 and 63 projecting therefrom and situated adjacent to one another to form a radial slot 60. "A pin 61 is fixed to the rear face of the shifter arm 49 to engage the slot. The opposite ends ofy the lugs lie in a diametrical line which is parallel tothe upper face of the shifter arm 51. The rear face of the shifter arm is provided with an arcuate groove 64 into which either lug 62 or 63-is adapted to move'upon reciprocation of the shifter arm 45 to therebyprevent movement of the arm 46. If the parts are in the position as shown in Figure 3, movement of the shifter'arm 46 to the left or right will move the portion 64 or 65 of the upper face of the arm 51 into the path of movement of the lug 62 or 63 respectively, thereby preventing movement of the shifter arm 45. It is thus seen that an interlock has` been provided between the arms 45 and 46. A further interlock has been rovided between the arm 44 and the pair o arms 45 and 46 whereby upon movement ofI either arm 45 or 46 to a power transmitting position, movement of the arm 44 will be prevented or if the arm 44 has been moved` to al power transmitting position shifting of either arm 45 or 46 will be prevented. To this end av mutilated gear, such as 66, is pivoted to the end of a stud shaft 67 and provided upon one face with a pair of parallel lchordal grooves 68 and 69. Each arm. 49 and 51 is provided with locking members 70 and 71 respectively. As shown in Figure 6, when the parts are in vneutral position the recess 7 2 formed in each yarm is in such a position as to permit rotation of the gear, while upon movement of either the arm 70 or the arm 71 a. projecting portion, such as 73, will enter a chordal groove and prevent rotation Vof the gear and thereby prevent shifting ofarm 48. Or if the gear 66 is rotated from 'neutralvposition by movement of arm 44, the grooves'GS and' 69'will be moved out of register with the portions 73 and thereby prevent movement of either arm 45 or 46. Dete'nt means have been j pin 58 journaled inthe provided, such as the spring pressed plungers 4, for maintaining the parts in adjustedl position. t

It should now be a parent `that a transmission has been providiad adapted for general application to a machine tool, where variations in therange of movement of a part is desired, in whichl is vcombined a variable speed transmission and a plurality of' back gear sets for use Ain conjunction therewith to increase the range of the variable speed transmission and of control mechanism for the back gear sets having interlocking means to prevent the use of more than one at a time.

j hat which is claimed is:

1. A transmission and..control mechanism for a machine tool comprising a variable y speed transmission, a series of back gear multipliers and a' nal member in serial tion, a pair of control members each connect- A ed to a"separate back gear unit, and a single control member connected to another back vgear unit, and linterlocking means to prevent the movement of more thanone control member at a time. i

3. A transmission and control mechanism for a machine tool comprising' a v'variable speed actuator, a final driven member, three setsof shiftable speed changing units4 mounted in interposed relation between said actu- `ator and the driven member, individual control means for eachof said shitable units and a triple interlock to prevent the movement ofmore than one unit at a time.

4. A transmission and control mechanism for a machine tool comprising a variable speed actuator, a member to be driven therefrom, Aan intermediate shaft adapted tol be driven in a forward or a reverse dlrection by said actuator, a plurality of gears on said driven member, a pair of shiftable gear couplets on said intermediate shaft means to shift said couplets to any one of four diferent power transmitting positions, 1an idler gear in constant mesh vwith one of said shiftable gears, and an additional shitable ear interposed between said idler and said driven member, and means to shift said gear into meshl with a gear on said driven member to effect an additional speed ratio between the shaft and member.

5. A transmission and control mechanism foramachine' tool comprising a variable speed actuator, 4a final driven member, a first, secf sa ond and third shiftable unit interpgsable between said actuator and in'al mem r for the. transmission of power from one to the other individual means for shifting the first and second units,', an interlock between said means to permit actuation of only one at a time, means to shift the third unit and interlock means between said third shifting means and the first pair of shifting means to prevent actuation of said third means when either one of said first two means have been moved to a power transmitting position.

6. A transmission and control mechanism for a machine tool comprising a driving member, a driven member,'an intermediate shaft,

means to actuate said shaft from the driving member in a forward or reverse ,direction, a plurality of shiftable power transmitting elements actuated by said Yintermediate shaft comprising a pair of shiftable gear couplets and av single shiftable gear, individual arms for shifting said couplets and said gear, aninterlock to prevent the acv tuation of more than one at a time, including a rotatable disk, means on one shifter arm upon movement to a power transmitting position to rotate said disk to a position preventing movement of a second arm, and additional means actuated thereby for preventing movement of a third arm. Y

7. A transmission and control mechanism for a machine tool including a driving member, a driven member, and three shiftable units interposable therebetween forlthe transmission of a plurality of speeds from one to P the other, individual shifter rods for each of said units, interlock means between a pair of said shifter rods to permit movement of only one at a time, additional interlock means `between said pair and the third shifter rod to preventactuation thereof when either of first gear and the other gear thereof with said second gear to eifect cou ling, of the driven shaft to the driven memlger in two different speed ratios, and means interposable between said second gear and' its corresponding mat- 70 ing gear of the couplet for'connecting the shaft to the member in an additional speed ratio comprising a pinion constantly meshing with said mating gear, a shiftable couplet having a gear meshing with the pinion for 75 constant rotation thereby, and means to shift the last named couplet to mesh the other gear thereof with said second gear on the member.

9. A variable speed transmission having in combination a driven shaft, power means for 8 actuating said shaft at a plurality of speeds and in opposite directions, a final member,

a pair of differentlyl sized gears spacedon the member, a shiftable gear couplet mounted on the driven shaft between said gears for 8.5 movement inv opposite directions into mesh therewith to connect the shaft in diiferent speed ratios with said member, said couplet having a neutral position, means for operatively connecting a gear of said couplet with 9 its corres onding matinggearon the member to e ect an additional speed ratio between the'parts when said couplet is in a neutral position comprising a wide faced pinion in constant mesh with the gear of said couplet 95 vand a pair of gears mounted on a shaftfparallel to the pinion, one of which is in 'oonvstant engagement therewith and the other shiftable into mesh with said matingegear the first pair is lin power transmittingvposii tion', including a rotatable member having a gear segment on its periphery Aand a pair of parallel chordal grooves o'n one face thereof,a rack arm integral with said third shifter engaging said gear segment, individual arms ,integral with the first pair of Shifters and extending parallel to one another andin overlying relation with said grooves, said arms having nprojections for engaging said grooves upon movement of either to a-power transmittlng positionto prevent rotatlon of the circular member, and thereby movement of the third shifter rod.

8. A transmission for a machine tool comprising a change speed transmission, a reverser, a 'driven shaft actuable at'various speeds and in opposite directions by said transmission through the reverser in serial power transmitting relationship. an ultimate y driven member having a first and second gear thereon, a gear, coupleton the driven shaft shlftable to mesh one gear thereof with said.

on the member whereby the shaft may cou- 100 led to the member through saidmating gear in two 4different speed'ratios.

In testimony whereof I aiiix my signature.

LESTER 4F. NENNINGER. 105 

